Claims
- 1. A method of producing agglomerates well suited for use in an iron producing blast furnace from a fine iron ore as a principal raw material, comprising the steps of:
- adding a fluxing material and a solid fuel to a fine iron ore having a dominant particle size of less than 5 mm;
- forming said material into first and second groups of pellets or briquettes of a size between 10 and 20 mm.phi., wherein each of said pellets or briquettes of the first and second groups is formed into a two-layer structure, said two-layer structure consisting of a core portion containing 0.3 to 1.0% by weight carbon and a shell portion containing 1.0 and 4.5% by weight carbon and wherein each of said pellets or briquettes of said first group contains 2 to 3% by weight of carbon and each of said pellets or briquettes of said second group contains between 0.5 and 1.0% by weight carbon;
- charging said first and second groups of pellets onto a travelling grate-type furnace in an upper layer and a lower layer, said upper layer consisting of said first group of pellets or briquettes and said lower layer consisting of said second group of pellets; and
- firing said pellets or briquettes in said travelling grate-type furnace including an updraft drying zone, a downdraft drying zone, an ignition zone and a suction burning zone.
- 2. A method according to claim 1, wherein said solid fuel is powdered coke, semicoke, pulverized coal, or petroleum coke.
- 3. A method according to claim 1, wherein said firing in said travelling grate-type furnace is effected by charging, after the end of a drying step, a carbonaceous matter of a particle size between 0.1 and 5 mm onto the surface of said upper layer charge as a heat source for said firing.
- 4. A method according to claim 1, wherein the waste heat of said suction burning zone is used as a heat source for said updraft drying and said downdraft drying.
- 5. The method of producing agglomerates according to claim 1 wherein said starting materials consisting of fine iron ores, fluxing materials and solid fuel are supplied to each of two pelletizing sections of a pan-type pelletizer while the binder is added, for producing pellet-like formed mass, said pan-type pelletizer having its pan divided into said two pelletizing sections, a circular central portion and a ring-like outer portion, characterized in that the content of the solid fuel in said starting materials is lower in the ring-like portion than in the central portion, thereby producing said pellets of double-layer structure with amounts of solid fuel in the core and shell portions being 0.3 to 1.0% and 1.0 to 4.5%, respectively.
Priority Claims (1)
Number |
Date |
Country |
Kind |
56-106869 |
Jul 1981 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 396,380, filed July 8, 1982 and now abandoned.
US Referenced Citations (3)
Foreign Referenced Citations (2)
Number |
Date |
Country |
55-107741 |
Aug 1980 |
JPX |
56-2134 |
Jan 1981 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
390380 |
Jul 1982 |
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